KR100966181B1 - Network interface entity selection method of a mobility management entity - Google Patents

Abstract

The present invention relates to a method for selecting a network interworking entity of a mobility management entity, wherein the mobility management entity considers the service requirements of the mobile terminal and the processing capacity of the network interworking entity, and thus the service requirements of the mobile terminal and the network interworking entity. Comprising a group including at least one network interworking entity that satisfies the processing performance requirements of the network, and considers the location and network topology of the mobile terminal among the network interworking entities included in the group In order to improve the performance of the mobile communication system by implementing the optimal network interworking entity.

Mobility Management Object, Network Interworking Object, Mobile Communication System, Base Station, Cell

Description

Network interface entity selection method of a mobility management entity

The present invention relates to a method for selecting a network interworking entity of a mobility management entity, and more particularly, to a technology for selecting a network interworking entity by the mobility management entity of a mobile communication system when the mobile terminal is initially registered.

The present invention is derived from the research conducted as part of the IT new growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [Task Management Number: 2005-S-404-23, Project Name: 3G Evolution Access System] .

In order for a mobile station to send and receive a packet network and a traffic in a mobile communication system, an appropriate network interworking entity should be selected among a plurality of network interworking entities connecting the mobile terminal and the network by the mobility management entity of the mobile communication system at the initial registration. do.

The mobility management entity may be a mobility management entity (MME) for 3GPP, or a base station controller (BSC) for CDMA 2000.

On the other hand, the network interworking entity may be a serving gateway (Serving GW) in the case of 3GPP, and may be a Packet Data Serving Node (PDSN) in the case of CDMA 2000.

FIG. 1 is a diagram illustrating a 3G Generation Long Term Evolution (LTE) system configuration.

Packet data transmission in a 3G LTE system is performed by a UE and an operator through a PDN gateway, a serving gateway, and an eNodeB of an Evolved Universal Terrestrial Radio Access Network (E-UTRAN). It is made between operators' IP service networks.

Since the 3G LTE system exchanges packets based on IP (Internet Protocol), one base station included in the E-UTRAN can be interworked with multiple MMEs or multiple serving gateways, and the relationship between them is 1: N. Can be interfaced with a relationship of N: 1.

Accordingly, a specific mobile station performs initial registration and at the time of service session establishment (Default IP Bearer and Dedicated IP Bearer), a serving gateway that is most suitable among a plurality of serving gateways connected to an eNodeB for load balancing purposes. You need to choose.

When the mobility management entity of the mobile communication system selects an appropriate network interworking object from among a plurality of network interworking objects connecting the mobile terminal and the network, the present inventors provide an optimal network based on the environment information related to the network interworking object, which is a traffic transmission path. We have been working on a technique for selecting linked objects.

The present invention has been invented in view of the above, and relates to a network interworking entity including service requirements of a mobile terminal, processing capacity of the network interworking entity, location of the mobile terminal, and network topology. An object of the present invention is to provide a method for selecting a network interworking object of a mobility management entity that can select an optimal network interworking object based on environmental information.

According to an aspect of the present invention for achieving the above object, in the present invention, the mobility management entity considering the service requirements of the mobile terminal and the processing capacity (capacity) of the network interworking entity, the service requirements and network of the mobile terminal Compose a group including at least one network interworking entity that meets the processing performance conditions of the interworking entity, and among the network interworking entities included in the group, a location and a network topology of the mobile terminal. In consideration of the above, the optimal network interworking object is selected.

The present invention provides an optimal network based on environmental information related to a network interworking entity including service requirements of the mobile terminal, capacity of the network interworking entity, location of the mobile terminal, and network topology. Since the interworking object can be selected to distribute the load of the mobile communication system, it has a useful effect of improving the performance of the mobile communication system.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce the present invention.

In the 3G LTE system, a default IP bearer for IP signaling and traffic is set during an initial attach procedure of a UE. At this time, the MME selects a serving gateway (PDN) and a packet data network (PDN) gateway to interwork with a base station (eNodeB) requested by the mobile station, and provides a service to the mobile station using these gateways.

The serving gateway assigned at the initial attachment of the mobile station is used until it is reset through the node relocation procedure of the core network (CN) associated with the mobile station's handover. do.

FIG. 2 is a diagram illustrating a mobile terminal registration procedure of a 3G LTE system, in which a mobile terminal requests an initial registration (100) and a service session setup (Default IP Bearer and Dedicated IP Bearer) process 200 And a process 300 of initial registration and service of the mobile communication terminal. Since the specific processing procedure for the mobile terminal registration is outside the scope of the present invention, description thereof will be omitted.

The method for selecting a network interworking entity of the mobility management entity according to the present invention is performed between the process of requesting the initial attachment of the mobile terminal (100) and the service session establishment process (200).

In this case, the mobility management entity may be a Mobility Management Entity (MME) for 3GPP, a base station controller (BSC) for CDMA 2000, or the like. On the other hand, the network interworking entity may be a serving gateway (Serving GW) in the case of 3GPP, and may be a Packet Data Serving Node (PDSN) in the case of CDMA 2000. In the present invention, a 3G LTE system will be described as an example for convenience.

3 is a diagram illustrating a connection example of a base station and an MME / serving gateway in a 3G LTE system. A base station (eNodeB) is located in each cell, and each base station (eNodeB) is interworked with an MME for a control interface, and a serving gateway for a data interface. Interlocked.

As shown in FIG. 3, one base station (eNodeB) may be linked with a plurality of MMEs and a plurality of serving gateways according to a system installation method, and when performing a registration procedure for a specific service, The MME is selected, and a serving gateway is selected by the selected MME.

In the figure, Cell # 01 is associated with Serving GW # 01 and Serving GW # 04, and Cell # 02 is Serving GW # 01 and Serving Gateway. You can see that it is linked with (Serving GW) # 03.

A method for selecting a network interworking entity of a mobility management entity according to the present invention is a serving GW of 3GPP for a data interface of a base station in a mobility management entity such as an MME of 3GPP or a BSC of CDMA 2000. Network interface entity such as CDMA 2000, PDSN (Packet Data Serving Node), etc., the service requirements of the mobile terminal and processing performance of the network interworking entity, location and network of the mobile terminal The optimal network interworking entity can be selected based on the environmental information related to the network interworking entity including the topology.

To this end, the method for selecting a network interworking entity of the mobility management entity according to the present invention uses environmental information as illustrated in Table 1. Such environmental information may be obtained from an operation management module such as OAM (Operation, Administration and Maintenance), which defines a methodology for presenting standards and a methodology for providing the operation / maintenance / maintenance function of the communication network. It can exist as an internal function of an object or as an external function object.

According to the method for selecting a network interworking entity of the mobility management entity according to the present invention, the mobility management entity selects the network interworking entity during the registration process of the mobile terminal using the environment information illustrated in Table 1, in which two aspects are described. Should be considered First, the service requirements of the mobile terminal and the processing capacity (capacity) of the network interworking object should be considered. Second, the mobile interworking entity should be minimized even if the mobile terminal to be registered currently moves.

Table 1

Setting information Explanation Network Interworking Object List (L _sgw ) List of network interworking objects controlled by mobility management objects List of base station and interoperable network interface entity (L _{sgw .i_ enb .n)} List of network interworking objects that can interwork with base station n A list of available base stations in conjunction with the network interface entity (L _{enb .i_ sgw .n)} List of base stations that can interwork with network interworking entity n A neighboring base station list (L _{neighenb .i_ enb .n)} List of base stations in neighbor cell adjacent to base station n Processing Performance of Network Interworking Objects (C _{sgw .i} ) Total serviceable capacity of network interworking entity i

The mobility management entity stores the information set in Table 1 in the form of a set, and capacity information is stored as a processable information amount. For example, referring to the environment information setting example based on the drawing shown in FIG. 3, it is as follows. In this case, sgw.n refers to n network interworking entity and enb.n refers to n base station.

(Network Linked Object List)

L _sgw = {sgw.1, sgw.2, sgw.3, sgw.4}

(List of network interworking objects compatible with base station 1)

_{L sgw .i_ enb .n = {sgw.1} , sgw.4}

(List of base stations that can be linked with network interworking object 1)

L _{enb .i_ sgw .1} = {enb.1, enb.2, enb.3, enb.4}

(List of base stations in neighboring cell adjacent to base station 3)

L _{neighenb .i_ enb .3} = {enb.1, enb.2, enb.4, enb.5, enb.6}

Processing Performance of Network Interworking Object 1

C _{sgw .1} = c

4 is a flowchart illustrating an example of a method for selecting a network interworking entity of a mobility management entity according to the present invention.

As shown in the figure, in the method for selecting a network interworking object of the mobility management entity according to the present invention, the mobile management entity identifies the base station from the base station in step S110 as the mobile terminal requests initial registration in the registration process of the mobile terminal. A network interworking object selection request message including information is received.

At this time, the network interworking entity selection request message may further include resource information ( _{Rue . Default} ) required for setting a default IP bearer. Resource information required for setting the default IP bearer is used when establishing a service session during the registration process of the mobile station.

The mobility management entity that receives the network interworking object selection request message in step S110 considers the service requirements of the mobile terminal and the processing capacity of the network interworking entity in step S120, and interworks with the service requirements of the mobile terminal. A group including at least one network interworking entity that meets the processing performance requirements of the entity is configured.

Next, the mobility management entity selects an optimal network interworking entity from among the network interworking entities included in the group configured by the step S120 in consideration of the location and network topology of the mobile terminal in step S130. .

When the network interworking entity selection is completed by the step S130, the mobility management entity transmits a network interworking entity selection response message including the selected network interworking entity identification information to the base station which transmitted the network interworking entity selection request message in step S140.

Thus, by doing so, the present invention provides the environment information related to the network interworking entity including service requirements of the mobile terminal, processing capacity of the network interworking entity, location of the mobile terminal, and network topology. Since the optimal network interworking entity can be selected based on the above, the load of the mobile communication system can be distributed, and thus the performance of the mobile communication system can be improved, thereby achieving the object of the present invention.

In detail, step S120 configures a group including at least one network interworking entity that satisfies the service requirements of the mobile terminal and the processing capability of the network interworking entity through the process illustrated in FIG. 5. 5 is a flowchart illustrating a group configuration procedure of a method for selecting a network interworking entity of a mobility management entity according to the present invention.

First, the mobility management entities are the mobile station, the cell (Cell) the base station and the interworking network interface entity list (L _{sgw .i_ enb .n)} capable of performing a registration process in step S121 is extracted. At this time, the mobile terminal to a cell (Cell) and a base station linked list of the network interface entity can (L _{sgw .i_ enb .n)} for performing the registration process can be extracted from the environmental information illustrated in Table 1 above.

If the linkable entity does not exist, the registration procedure of the mobile terminal is rejected. If one or more linkable entities exist, the mobility management entity considers the service requirements and processing capabilities of the network linked entity in step S122. extracting the service network interface entity available from the network interface entity list (L _{sgw .i_ enb .n)} extracted by the step S121 to constitute a group. The list of serviceable network interworking objects included in this group is called L _{sgw .s} .

At this time, since the processing capability of the network interworking entity in step S122 is known from the bearer allocation information of the mobile station in which the network interworking entity is currently registered, the total capacity that can be processed by the network interworking entity (C _sgw ). It can be obtained using the difference of the capacity (R _{ue .i} ) of the bearer (Bearer) allocated in the. This can be expressed as follows. When the registration procedure of the mobile terminal is required, the _{Csgw . c} is represented, and the bandwidth information (capacity of the allocated bearer) allocated to the mobile station i is R _{ue . In i} , n represents the number of registered mobile terminals.

On the other hand, since the mobile station initially includes only quality of service (QoS) information for setting a default IP bearer, an estimated value (λ) required for setting a dedicated IP bearer that will occur later. In consideration of this, a group may be formed by extracting the list of serviceable network interworking objects L _{sgw .s} .

That is, the group consists of a set of _serviceable network interworking entity list L _sgw.s that satisfies the following expression.

C _{sgw .c} ≥ R _{ue . default} + λ

Since the mobile terminal has mobility, the overall system performance can be improved by selecting a network interworking entity having the smallest possible relocation of the network interworking entity in consideration of handover. That is, if the mobile station has the same probability of mobility toward the cell, the probability of relocation of the network interworking entity occurs when there are many neighbor cells of the cell performing the registration procedure. This decreases.

In order to satisfy this condition, step S130 selects an optimal network interworking entity by performing the following detailed operations.

In step S120, the group having the network interworking entities that satisfies the service requirements of the mobile station and the processing capability of the network interworking entity is L _sgw.s = {sgw.1, sgw.2}. Assume that the network interworking objects sgw.1 and sgw.2 areas are as shown in FIG.

7 is a flowchart illustrating an optimal network interworking entity selection procedure of the method for selecting a network interworking entity of a mobility management entity according to the present invention.

Mobility management entity in step S131 and extracts the neighbor cells (Neighbor Cell) List (L _{neighenb .i_ enb .n)} for each network interface entity included in the group constituted by the step S120. At this time, the neighboring cells (Neighbor Cell) List (L _{neighenb .i_ enb .n)} can be extracted from the environmental information illustrated in Table 1 above. For example, referring to FIG. 6, L _{neighenb. I_ enb. 1} = {enb.2, enb.3, enb.4}.

Then, the mobility management entity extracts a list for each network interface entity per neighboring cell that can be a base station service in step _{S132 (μL sgw .i_ enb .n)} . In this case, the neighbor cell list for each network interworking entity capable of serving the base station is simultaneously included in the list of base stations interworking with the corresponding network interworking entity and the base station list of the cell adjacent to the base station of the corresponding cell. Extractable from

For example, referring to FIG. 6, μL _{sgw .2_ enb .1} = {enb.2, enb.4} and μL _{sgw .1_ enb .1} = {enb.2, enb.4, enb.5}. .

The mobility management entity then constructs a neighbor cell tree using the neighbor cell list for each network interworking entity extracted in step S133.

At this time, the base station of the cell to which the mobile terminal registers is set as the root node, and the base station of the neighboring cell of the root node is set as the child node, and the parent node and the child node. A neighbor cell tree is formed by forming a relationship and connecting the formed parent node and child node.

In addition, by setting the base station of the neighboring cell of the child node as a child node of the child node to form a child node relationship with the parent node, the neighbor cell tree is n by repeating the connection between the formed parent node and the child node (Edge). It has a car's depth (Depth). On the other hand, when a neighbor cell of a child node is a parent node or a sibling node, it does not edge.

The meaning of the nth order-by-depth relationship indicates the neighbor relationship between the base station of the cell to which the mobile station is to register and the neighboring cell, that is, the child node connected to the root node. It can be seen that the mobile terminal is adjacent to the cell to be registered, and the child node connected to the child node can be seen to be adjacent to each other with one or more cells.

Accordingly, the degree of densities of neighbor cells of the cell base station to be registered can be known through the nth-order depth. 8 is a diagram illustrating an example of a network interworking entity neighbor cell tree.

Finally, in step S134, the mobility management entity selects a network interworking entity having a high degree of neighbor cell density from the neighbor cell tree configured in step S133.

Neighbor cell density can be extracted by using the number of neighbor cells in consideration of network topology and affecting mobility among network interworking entities that a mobile station can perform the registration procedure. The following equation is one example of the equation for obtaining the neighboring cell congestion degree (D _{sgw .i_ enb .n).} In the equation, N _k is the number of neighboring cells having kth-order depth, and α is an exponent of 0 <α <1.

Therefore, even when the mobile terminal moves, the network interworking entity having a high degree of neighbor cell density decreases the probability of relocation of the network interworking object. Therefore, the network interworking object having the highest neighbor cell density is moved. Final selection is made as the network interworking entity to be used for the registration procedure and service of the terminal.

As described above, according to the present invention, when a plurality of network interworking devices are linked to the mobility management entity of the mobile communication system, the service requirements of the mobile terminal, processing capacity of the network interworking entity, location of the mobile terminal, and By selecting the optimal network interworking object based on the environment information related to the network interworking object including network topology, the overall system load can be distributed, and the neighbor cell of the cell to provide service ) By selecting a network interworking entity in which many neighbor cells exist in consideration of density, the relocation procedure of the network interworking entity can be minimized.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. .

The present invention can be industrially used in the technical field and its application technology in which the mobility management entity of the mobile communication system selects an appropriate network interworking entity.

1 is a diagram illustrating a 3G LTE system configuration

2 is a diagram illustrating a mobile terminal registration procedure of a 3G LTE system

3 is a diagram illustrating a connection example of a base station and an MME / serving gateway in a 3G LTE system;

4 is a flowchart illustrating an example of a method for selecting a network interworking entity of a mobility management entity according to the present invention;

5 is a flowchart illustrating a group configuration procedure of a method for selecting a network interworking entity of a mobility management entity according to the present invention;

6 is an exemplary diagram of a base station cell interworking with a network interworking entity;

7 is a flowchart illustrating an optimal network interworking entity selection procedure of the method for selecting a network interworking entity of a mobility management entity according to the present invention.

8 illustrates an example of a network interworking entity neighbor cell tree;

Claims (12)

delete a) step a1) of extracting a list of network interworking entities interoperable with a base station of a cell to which a mobile station performs a registration procedure; and a1) in consideration of service requirements of the mobile terminal and processing capability of the network interworking entity. A2) extracting serviceable network interworking entities from the list of network interworking entities extracted by the step and forming a group; b) selecting an optimal network interworking entity among network interworking entities included in the group configured by step a) in consideration of the location and network topology of the mobile terminal; Method for selecting a network interworking object of a mobility management object, characterized in that it comprises a. a) a group including at least one network interworking entity meeting the service requirements of the mobile terminal and the processing capability of the network interworking entity in consideration of the service requirements of the mobile terminal and the processing capability of the network interworking entity; Organizing a group); b) step b1) of extracting a neighbor cell list for each network interworking entity included in the group configured by step a), and extracting a neighbor cell list of each network interworking entity capable of serving a base station; B3) configuring a neighbor cell tree using the neighbor cell list for each network interworking entity extracted by step b2), and neighboring from the neighbor cell tree configured by step b3). B4) selecting a network linked object having a high cell density; Method for selecting a network interworking object of a mobility management object, characterized in that it comprises a. The method of claim 2, The processing capability of the network interworking entity in the step a2) is obtained by using the difference of the capacity of the preset bearer from the total capacity that can be processed by the network interworking entity. Way. The method of claim 4, wherein The method for selecting a network interworking entity of a mobility management entity, wherein the processing capability of the network interworking entity is obtained by further reflecting an estimate required for a later set of dedecated IP bearers. The method of claim 3, wherein The neighbor cell list for each network interworking entity capable of serving the base station service extracted in step b2) is a base station list interworking with the corresponding network interworking entity and cells included in the base station list of the cell adjacent to the base station of the corresponding cell. A method for selecting a network interworking object of a mobility management object. The method of claim 3, wherein In step b3), the base station of the cell to which the mobile station registers is set as a root node, and the base station of a neighboring cell of the root node is set as a child node. A method for selecting a network interworking object of a mobility management entity, comprising forming a child node relationship and forming a neighbor cell tree by connecting the formed parent node and the child node. The method of claim 7, wherein The neighbor cell tree is further configured by establishing a base station of a neighboring cell of the child node as a child node of the child node, forming a child node relationship with the parent node, and connecting the formed parent node and the child node. Method for selecting a network interworking object of a mobility management object, characterized in that. The method of claim 8, A method for selecting a network interworking object of a mobility management entity, wherein the neighboring cell of the child node is not a parent when the neighboring cell is a parent node or a sibling node. The method according to any one of claims 2 to 9, c) receiving a network interworking entity selection request message including base station identification information from a base station in a registration process of a mobile terminal; The method for selecting a network interworking object of a mobility management object, further comprising. The method of claim 10, d) when the network interworking entity selection is completed, transmitting a network interworking entity selection response message including the selected network interworking entity identification information to the base station which has transmitted the network interworking entity selection request message; The method for selecting a network interworking object of a mobility management object, further comprising. The method of claim 10, The method for selecting a network interworking entity, wherein the network interworking entity selection request message further includes resource information necessary for setting a default IP bearer.

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